What is the use of final keyword in java?

Good question, mate. The final keyword in Java is a way to lock things down. It’s all about making something unchangeable once it has been declared. You can use it in three main spots.

Slap it on a variable, and it becomes a constant. You can only assign its value once.

Put it on a method, and subclasses can't override it. Its behaviour is set in stone.

Use it on a class, and that class can’t be extended. It's the end of the line for inheritance.

It’s a powerful tool for creating immutable objects and ensuring your design remains solid. It helps you write more robust and predictable code. Straight up.